project file on extension board

1. K.V.N.E.R
PHYSICS PROJECT
BBBBBWORK
SUBMITTED BY: SUBMITTED TO:
RISHABH KUMAR MR. VIVEK CHAUHAN
12-C
ROLL N0.-5644106 SESSION-2018-19
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ELECTRICAL EXTENSION BOARD

2. Certificate
This is certify that “Rishabh Kumar” of class XII,
KV NER ,Bareilly has successfully completed his
“Physics Project Work” on “Electrical Extension
Board”. During academic session 2018-19 as per the
guidelines issued by the CBSE.
Roll no. : 5644106
Teacher’s Signature Examiner’s Signature
Date: Principal

3. Acknowledgement
I would like to express my special thanks to my
teacher “Mr.Vivek Chauhan” as well as our principal
“Mrs. Aparna Saxena” who gave me the golden
opportunity to do this wonderful project on the topic
“Electric Extension Board” ,which also helped me in
doing a lot of research and I came to know about so
many new things.
I am really thankful to them.

4. Content
 INTRODUCTION
 AIM
 THEORY
 APPARUTUS REQUIRED
 ASSEMBLING AN EXTENSION
BOARD
 SAFETY MEASURES
 BIBLIOGRAPHY

5. INTRODUCTION:
We must have seen electrical sockets fixed on the walls of wer home. If we wish to use an
electrical appliance such as a table lamp or an iron at some distance from the wall, we need
an (electrical) extension board. Similarly, in a physics laboratory, we maybe required to use
an extension board particularly when manystudents are working on a table or when many
electrical Iinstruments are to be used. Ari extension board provides for: more than one
electrical socket. These sockets are connected to a plug through a long three- Icore
electrical wire. When this plug is inserted in the socket on a wall of the I laboratory,
electricity becomes available at the sockets of the extension board. And that is why an
extension board is such a useful laboratory tool.

6. AIM:
The main purpose of this project is to enable we to learn how to fabricate an electrical
extension board.
After doing this project, anyone will be able to: identify the live, neutral and terminals of a
socket and corresponding wires in a three-core electrical wire.
THEORY:
We have learnt that household electricityconnection is provided through a heavy cable
which has two wires. These two wires are insulated from each other. One of these wires is
called the live (L) wire and another is called the neutral (N) wire. The electric supplyis AC
(alternating current) and the live wire is alternatelyat positive and negative potential of
220V with respect to the neutral wire. The potential of the neutral wire is zero because it is
earthed at the local electric sub-station. Therefore, when an electrical appliance is plugged
to AC mains, charge flows from the live wire, through the appliance to the neutral wire when
the live wire is at positive potential and vice-versa when the live wire is at negative
potential.
The electrical connection to the mains of the physics laboratoryis also provided through a
two-core heavy cable. The electricitysupplied is used for lighting, running electrical and
electronic equipment etc. Household electrical wiring comprises a number of parallel
circuits. It means that all live wires should be connected at one point. Separate electrical
circuits are used for lighting and power.
The switch such as is always connected in the live (L) wire of the circuit so that when it is
off, the socket (or the bulb holder) is not live. However, if the switch is connected in the
neutral wire, the socket is live even when the switch is in off position. In such a condition,
anyone touching the socket or the bulb holder would get a shock. For this reason, anyone
should fix switches in the extension board along the live wire.

7. The basic activities involved in assembling the extension board are to wire
switches, sockets and plugs in accordance with a circuit diagram.
A. Electrical wires
Electrical wires are made of copper because copper is a good conductor of electricityand
relatively inexpensive Generally, for equipment used in a typical
physics laboratory, it is safe to assume that not more than 15 A current would flow through
the cable at anyinstant of time
B. Socket and plug
Refer to Fig which show a 15A three-pin socket, and a 15A three-pin plug,
C. Switch
The electric switch has only two terminals. It is always connected along the live wire in a
circuit.

8. APPARATUS REQUIRED:
1 WOODEN BOX
Good quality 5m single-core electrical wire
Half meter single core electric wire
2 switches (15 A)
2 three-in-one (5A and 15A) sockets
1 two-in-one(5A) socket
1 electric indicator
1 three-pin plug
1 electric plain board with holes

9. ASSEMBLING THE EXTENSION BOARD:
The basic activities involved in assembling the extension board are to wire
switches, sockets and plugs in accordance with a circuit diagram.
1.Take out the top of the wooden/plastic box for drilling holes in it to fix the sockets and
switches . With a pencil, mark the points shown in Fig A. for holes. Use a hand drill to drill
holes of appropriate size at these points. Fix the sockets and switches in their appropriate
positions on the top of the box with screws.
Fig A.
2.This diagram (Fig. B) is the labelled version of the circuit diagram of the extension board
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10. Note that all the terminals of sockets and switches in Fig.B are numbered.
We just have to join these numbered terminals as per the instructions
given below using the single core wire . We will have to cut this wire into pieces of
appropriate length:
a) Connect 2 and 5,
b) Connect 1 and 9.
c) Connect 4 and 8.
d) Connect 6 and 9.
e) Connect 7 and 8.
f) Connect 9 and 10.
g) Connect 8 and 13.
h) Connect 11 and 14.
Now all the internal electrical connections of the extension board are complete. Now we
joined the 5m long three-core wire with the extension board so that it can be plugged into
the wall socket.
3. Connect the live wire to point 1 (the upper end of switch) of the extension board.
4.Connect the neutral wire with point 4 (the neutral terminal of socket).
5.Connect the other end of the wire with a three-pin 15A plug
connecting live and neutral wires at the appropriate terminals.
6.Now place the top on the box in such a waythat all electrical
connections are concealed in the box.
7. Fix the top on the box with the help of screws.
8.Extension board is ready for use. Insert the plug fixed at one end of
the wire into a wall socket and switch it on. To check that
electricity is available at wer extension board; we used an electrical
tester

11. CIRCUIT DIAGRAM:
SAFETY MEASURES:
1. While fixing stranded copper wires at the terminals of the sockets,
switches and plug, we must twist the strands properlyso that no strand
remains loose. This is necessary to avoid anyshort circuit.
2; In electrical connections, nothing can be as irritating and riskyas loose
connection. Therefore, properly tighten the screws on the terminals of the
sockets and switches.
3. Since water conducts electricity, we should always dryour hands
before switching-on or off any electrical appliance or equipment.
4. Do ensure that the switches on the extension board have been put along
the live wire.

12. Bibliography
 https://www.google.com